Structural and Value-Based Analysis of Niyāresh in the Soltaniyeh Dome Architecture: Evaluating Conservation Interventions Using Numerical Modeling and Finite Element Analysis

Abstract

This study aimed to analyze the structural behavior (niyāresh) of the Soltaniyeh Dome, focusing on the impact of conservation interventions—particularly the reinforced concrete ring—on its structural stability and the tangible and intangible architectural values of this prominent Ilkhanid monument. The research employed numerical modeling using ABAQUS software to simulate the dome's structural response under different load conditions, both with and without the concrete ring. Geometric data were obtained through laser scanning and precise surveying, while material characteristics were defined based on technical standards. Stress and strain distributions were analyzed under static (gravitational) and dynamic (seismic) loads. The results indicated that the original design of the Soltaniyeh Dome, based on accurate structural principles, ensures high stability against gravity loads. The added concrete ring showed negligible improvement in gravitational performance but posed significant risks under seismic loads by concentrating stresses and limiting the dome’s natural flexibility. Comparative simulations demonstrated that the ring disrupts the balance of meridional and hoop stresses in the structure. The findings highlight that previous conservation interventions, particularly the concrete ring, may have compromised the dome’s seismic performance due to inadequate structural analysis. The study emphasizes the necessity for compatible conservation practices and context-sensitive materials in heritage restoration and underscores the importance of rigorous structural evaluations in future interventions.